Health insurers rise after CMS releases preliminary Medicare Advantage ratesThe shares of a number of health insurers are rising after the Centers for Medicare and Medicaid Services, or CMS, issued preliminary 2016 Medicare Advantage rates. According to Credit Suisse, the rates were favorable for health insurers. WHAT'S NEW: On Friday after the market closed, CMS issued a proposal for 2016 Medicare Advantage rates. The rates are preliminary and could change when CMS announces the final 2016 rates on April 6 of this year, the agency noted. In a note to investors earlier today, Credit Suisse analyst Ralph Giacobbe estimated that, under CMS' initial proposal, insurers would see rate changes of between -1% and +1%, depending on the risk that each insurer faces. The preliminary rates were "favorable" for insurers, since the rates were "in-line if not slightly better" than investors had expected, the firm stated. Moreover, CMS decided not to restrict at-home health risk assessments, as had been feared, and agreed to reduce the weighting of certain risk factors that had hurt previously certain plans with a higher proportion of low-income beneficiaries, acceding to a request by insurers. Insurers with the highest exposure to Medicare Advantage include Humana (HUM), UnitedHealth (UNH), and WellCare (WCG), the analyst stated. WHAT'S NOTABLE: After analyzing CMS' proposal, health insurer Aetna (AET) estimated that the proposal would cause government funding for its Medicare Advantage business to decline by about 1% in 2016. Aetna added that it is continuing to evaluate the changes outlined in the Advance Notice and their impact on the company and its Medicare Advantage members. OTHERS TO WATCH: Other publicly traded health insurance companies include Anthem (ANTM), AMERIGROUP (AGP), Centene (CNC), Cigna (CI), Health Net (HNT), Healthspring (HS), and Molina Healthcare (MOH). PRICE ACTION: In mid-morning trading, Humana climbed 5.3% to $164.43, UnitedHealth rose 2.6% to $115.56, WellCare gained 6.3% to $90, Aetna advanced 2% to $99.91, and Centene added 3.4% to $61.93.